No hassle headers for 66 dart w/360?

In 1977 i took in trade a set of Hooker 1 7/8 fenderwell race headers. From a friend that had them on his 1970 AAR cuda.with slip fit primary extensions for tuning. I didn't know if they would fit the 65 Dart with 340 i had, but they did! As i remember, i only had to cut the usual area for the tubes at the top of the inner fenderwells.